Approximately 80 officers and deputies are searching a South Pasadena park on Thursday morning for evidence on the whereabouts of a five-year-old boy who's been missing since last month, according to the Los Angeles County Sheriff’s Department.

An extensive search was already conducted at the park when the disappearance was first reported—authorities said on Wednesday that a “recent tip” has led investigators back to the area, reports the L.A. Times. Authorities declined to elaborate on the nature of that tip.

Thursday's search involved deputies on horseback, cadaver dogs, and drones. Lt. Joe Mendoza of the Sheriff's Department told the Times that, as a month has passed since the first search, "maybe there’s different scents that are available.” Deputy Sheriff Dan Paige told LAist that he expects today's search to wrap up at around 1 p.m.

The boy, Aramazd Andressian Jr., was first reported missing on April 22 by his mother, Ana Estevez, who said that she was supposed to meet him and his father for a scheduled drop off. Estevez and the father, Aramazd Andressian Sr., are separated and share custody of the child.

At around the time of the missing persons report, Andressian Sr. was found passed out by his car in Arroyo Park in South Pasadena. According to the the Sheriff's Department, Andressian Sr. was unable to account for his son's whereabouts and provided statements that were "convoluted and not consistent." Andressian Sr. was briefly held on charges of child endangerment and child abduction, but was released on lack of evidence.

On Wednesday, Sheriff's officials held a news conference to announce the new search and to reveal additional information, saying that the father had admitted to taking prescription drugs that were not prescribed to him, and that his BMW was doused with gasoline inside and out when authorities first discovered him. Authorities added that matches and a gas can were found inside the vehicle, and that a gas-soaked rag was discovered near the gas cap, reports ABC 7.

Estevez was also present at the conference, where she addressed the public for the first time. "There are no words to describe how heartbroken I am. Although I do not know his whereabouts, I do believe that Piqui is alive, missing his family and desperately wants to come home," said Estevez, referring to her son by his nickname.

Anyone with information is encouraged to call the Sheriff’s Department Homicide Bureau at (323) 890-5500. If you wish to remain anonymous, you can call Crime Stoppers at (800) 222-8477.