TAMPA — Before the sirens and stretcher arrived on a hot night in May, there had been only one call to police about 906 W Knollwood St. It came from the house's renter, Jason Westcott, and he was looking for help.

A man who had partied at Westcott's home was plotting to rob him. An itinerant motorcycle mechanic, Westcott didn't have much — two televisions and a handgun that once belonged to his brother were perhaps the most valuable possessions in his 600-square-foot house in Seminole Heights — but he was terrified by his would-be intruder's threats to kill him.

Police tracked down the suspect and warned him to stay away. Westcott, those close to him said, was left with a word of advice from the investigating officers: If anyone breaks into this house, grab your gun and shoot to kill.

On the night of May 27, as armed men streamed through his front door, Westcott grabbed his gun. But the 29-year-old didn't have a chance to shoot before he died in a volley of gunfire. And those who killed him weren't robbers.

They were police officers from the same agency he had enlisted to protect his home.

In the span of a few months, Westcott had become the target of an intensive drug investigation. On that Tuesday in May — a night when he typically baby­sat his sister's children at his house, according to his mother — he was fatally shot by a Tampa Police Department SWAT team executing a search warrant for marijuana.

Authorities told news reporters who swarmed to the scene that Westcott was dealing drugs and had sold pot multiple times, armed, to undercover Tampa police officers. During the raid, officials said, he "raised his gun and threatened the officers," who killed him in self-defense.

A month later, newly disclosed information raises questions about the narcotics investigation that led police to Westcott's door.

Despite police assertions that Westcott was a drug dealer, the SWAT team found only 0.2 grams — approximately $2 worth — of marijuana in the house, according to documents provided by the department in response to a public records request from the Tampa Bay Times.

The drug buys that preceded the raid were conducted not by undercover officers but by an informer, who purchased less than $200 of pot during repeated visits to Westcott's house over four months, the records show.

Police initially said that the investigation of Westcott's alleged drug dealing began because of neighbors' complaints. However, when the Times could find no neighbors who had called police and no records of the complaints, the department revised this assertion, saying the case began with a tip from the same informer who later bought the marijuana.

The only police records involving Westcott's home before the drug investigation are those related to his request for police protection from a robbery.

Westcott's live-in boyfriend, Israel Reyes, 22, also suspected of dealing drugs and present at the house the night of the raid, has not been charged with a crime.

"Nobody can believe that this happened to Jason. They can't understand how this could happen to Jason," said Westcott's mother, Patti Silliman of New Port Richey. "No one can figure this out."

'Not an exact science'

Last month, the Hillsborough State Attorney's Office concluded after a review that the two police officers who shot at Westcott — Cpl. Eric Wasierski and Officer Edwin Perez — were justified in the use of deadly force.

In an interview with the Times, Tampa police Chief Jane Castor defended the drug investigation at 906 W Knollwood and said she has seen no signs that the officers who killed Westcott acted inappropriately.

"Mr. Westcott lost his life because he aimed a loaded firearm at police officers. You can take the entire marijuana issue out of the picture," Castor said. "If there's an indication that there is armed trafficking going on — someone selling narcotics while they are armed or have the ability to use a firearm — then the tactical response team will do the initial entry."

Castor said the negligible amount of marijuana found doesn't necessarily cast doubt on the police informer's description of a high-volume drug operation. She pointed to other items uncovered in the search, including a digital scale, plastic baggies and jars with marijuana residue, as evidence that Westcott might simply have sold out of his drug inventory by the time the SWAT team showed up.

"I've gone in where there was an expectation that we would find a small amount and you would find kilos of narcotics. And then vice versa, where you were going in and you thought you were going to find multiple kilos and you found residue," Castor said. "It's not an exact science."

Police Department spokeswoman Laura McElroy, who made the inaccurate statements about undercover officers buying marijuana from Westcott and about calls regarding the house from neighbors, said her initial statements about neighborhood complaints were the result of conflicting information she received from detectives.

The police informer's role was not disclosed at the request of investigators, she said, who worried that because Westcott "only sold to a limited number of people out of his house" that the informer could be identified. McElroy said detectives believed Westcott sold to a larger circle of clients in clubs, an assertion Reyes denied in an interview.

While police maintain that the Westcott investigation was routine narcotics work followed by a properly conducted drug raid, it raises fresh questions for a department that has been buffeted by scandal during the past year, including a separate episode involving a problematic informer.

Reyes and Westcott's mother have hired Tampa lawyer TJ Grimaldi, who said he is investigating whether the Police Department used excessive force in executing its search warrant.

Reyes said he and Westcott were not hardened drug dealers, but habitual pot smokers who sometimes sold to acquaintances. He said they never kept more than 12 grams — a misdemeanor possession amount — in the house.

"We would just sell a blunt here and there to our friends or whatever. It was no crazy thing. There weren't people coming in and out of our house every day," he said. "It wasn't paying any bills. We were still broke . . . going to work every day."

If investigators had witnessed the sales firsthand rather than relying an informer, he said, they would not have called in a SWAT team prepared to face violent drug traffickers.

"That much force wasn't necessary for this little," Reyes said.

Dealer 'pays his rent'

The house at 906 W Knollwood St. is a shoebox of a building, standing unshaded amid rows of decaying bungalows on the west shore of the Hillsborough River.

When Westcott moved in almost two years ago, he put a used hot tub in the back yard and installed crown molding in the living room. He ripped the vertical blinds from the windows, filling the house with light. A circle of cinder blocks out back became a fire pit, surrounded on cool evenings by family and friends.

"Jason's the type of person that no matter where he goes, he always tries to fix something," Silliman said.

Westcott moved with his family to Florida from New York as a teenager. Sinewy, short and brown-eyed, he grew into an avid gearhead and trained as a motorcycle technician in Daytona Beach.

He met Reyes at an Ybor City nightclub. The two moved in together shortly afterward. Reyes said he felt lucky to forge a connection with Westcott in a city where gay men sometimes struggle to meet partners.

"He was the first guy who ever came over to my dad's house for Thanksgiving," Reyes said. "He was just like every other dude — worked on cars, didn't care what he looked like, funny."

Other than driving offenses, Westcott's only criminal record in Florida at the time of his death was an arrest for misdemeanor marijuana possession when he was 18. He pleaded guilty and adjudication was withheld. Reyes was in court in Pinellas County in 2012 for a misdemeanor charge of driving under the influence and again last year for failing to appear on a charge of driving with a suspended license, but otherwise has no criminal history in Florida, according to records.

Westcott and Reyes were sociable but often short on cash, those who knew them said. Sometimes they appealed to friends in the neighborhood for cash to supplement Westcott's income from intermittent jobs at motorcycle dealerships and Reyes' wages from working at a Starbucks.

"The sweetest thing about those boys was they tried so hard," said next-door neighbor JoAnn Tomlinson, 64.

Westcott's and Reyes' money problems were a source of annoyance for their landlord, Peter Zwolinski, an expressive Polish immigrant who was fond of his tenants despite their irregular rent checks. When a Tampa police officer told him on the night of the raid that Westcott and Reyes were drug dealers, Zwolinski said, "I basically laughed in his face."

"A drug dealer is paying his rent on time, and he doesn't have me bothering him for money every week," Zwolinski said. "You ever see a drug dealer whose phone was disconnected for a week at least every other month? I don't."

Poverty aside, Westcott and Reyes opened their house to friends and family. But at a cookout in October, their generosity reaped an unwelcome result.

A stranger who had showed up with one of their friends asked to borrow Westcott's phone. He then got on Facebook and messaged two other men about stealing his hosts' gun and TVs in a few days' time and "burning" (or killing) Westcott, according to police reports on the incident.

After discovering the messages the next day, Westcott called the police, who consulted with him over several days about how to handle the incident.

The crime ultimately did not take place, and officers identified the alleged conspirators and put them on notice, the police report states. Reyes said investigators told him and Westcott not to be afraid to use their gun to defend themselves if the suspects reappeared, an account Westcott also related to his mother.

McElroy denied that the detectives who worked the case made the statements the young men described about using the gun to kill robbers if they broke in.

The episode left the couple shaken. They bought a security system equipped with outdoor cameras.

Such surveillance arrays are sometimes viewed by police as a sign of drug trafficking or manufacturing. Reyes said the system, bought for less than $300, had nothing to do with their pot sales.

"We had those cameras because we were trying to protect ourselves," he said.

The cameras fed to a monitor in the living room that could be seen, looking across the house, from a corner of the bathroom. If there were ever a break-in, Silliman and Reyes said, Westcott's plan was to crouch there with his gun — kept on a shelf in his nightstand as he slept — to defend himself.

An informer appears

Westcott and Reyes didn't know it, but within months police were again watching their house, for a very different reason.

In mid February, according to a report by Tampa Officer Michael Schaff, an unidentified informer provided information that a "white male named 'Jason' " was selling marijuana from 906 W Knollwood St.

Between February and May, the informer was driven four times to the house by undercover officers, then went inside to buy quantities of pot at prices ranging from $20 to $60, according to a search warrant affidavit and police evidence records.

Those small amounts are not necessarily indicative of how much pot Westcott had on hand, McElroy said, since investigators generally seek to buy only small samples of drugs even when large quantities are available.

Castor said the informer told his handlers he had seen two different handguns at the house when buying drugs, although police later found only one.

Grimaldi, the lawyer for Silliman and Reyes, said that even if the drug deals outlined in police records did take place they didn't warrant a SWAT raid.

"Whether that stuff is correct or not, there is no indication that there were huge drug deals going on, or that there were plants or a grow house or anything like that," Grimaldi said. "Unless it's standard operating procedure to take SWAT to every single warrant, which I don't think it is, there's just no need for it."

Roy Bedard, a Tallahassee-based police consultant and expert witness on the use of deadly force, said a tactical raid would be prudent if investigators believed they were dealing with a large cache of drugs, which might be protected by gun-toting traffickers or booby traps.

"If it was a grow house, it could be exceptionally dangerous. You wouldn't want to send patrol officers," Bedard said. "It sounds to me like they had some reason to believe that this was a bigger operation than the search yielded."

The police raid that killed Westcott took place about 7:30 p.m. Westcott's mother said she spoke to her son on the phone for the last time several hours earlier. He planned to go to bed early because he and Reyes had been up late the previous night playing video games, she said.

Castor said that the tactical officers knocked on the front door and announced themselves, but that nobody inside answered. Finding the door unlocked, they let themselves into the house.

Reyes, who was sleeping on the couch in the living room, recalls rising groggily to find darkly uniformed men handcuffing him and saying "Police, narcotics."

Westcott was in the bedroom. Silliman's conjecture is that her son, afraid the men who had threatened to rob him in the fall had finally arrived, grabbed his gun and made for the protected vantage point in the bathroom where he could see his surveillance monitor.

He was shot near the doorway connecting the living room and the hallway between the bedroom and bathroom. Castor said Westcott appeared in the door pointing his pistol at officers, who fired on him five times with a semiautomatic shotgun and handgun.

Westcott never fired his weapon. Hit once in his arm and twice in his side, he collapsed on the tiles of the bathroom. Two of the slugs tore through the wall behind him, leaving splintered holes still visible from the outside six weeks later.

A SWAT team medic treated Westcott at the scene, and he was quickly moved out of the house on a stretcher. He was driven to a hospital, where he was pronounced dead.

Review ongoing

Police are still performing a customary internal review of the fatal shooting, but Castor said she believes that the tactical team followed policy. "The officers have a split second to make a decision when faced with somebody who's armed," she said.

Almost nothing is publicly known about the informer who supplied police with their information. Castor said the individual had worked as a confidential source for the department before and had a track record of providing reliable information.

She said the department is bound by state law to withhold details that could compromise an informer's safety. Castor requested that the Times not report that an informer was used in the Westcott investigation, arguing the disclosure could lead to the person's identification. The Times learned of the informer's role from public records on the case.

Westcott's death occurred as Tampa police are dealing with the fallout from another informer's misdeeds.

In May, news broke that a group of former department employees are the targets of a federal corruption probe because of suspicions that they may have participated in a tax-fraud scheme with former police informer Rita Girven.

"We are constantly reviewing how we utilize informants," Castor said, characterizing them as "a necessary evil" of law enforcement whose reports must be independently verified.

She said there is no broader problem with how Tampa police manage informers.

"We have sound policies on confidential informants — the use of them, oversight, payment, corroboration, when they're effective, when they're not," Castor said.

In Westcott's case, she added, "there is no indication that there is any problem with the information provided."

News researcher John Martin contributed to this report. Contact Peter Jamison at pjamison@tampabay.com or (813) 226-3337. Follow @petejamison.