The Hillsborough Sheriff's Office said a man shot and killed his cousin at a family home in Thonotosassa on Monday, then remained at the scene as a witness called 911.

Diquan Mills, 23, of Tampa was shot just before noon while visiting family at 9862 Timmons Road. That is where his cousin, Darrell Gadson, 38, lived, according to sheriff's Col. Donna Lusczynski.

A news release said Gadson is expected to be charged with second-degree murder.

He has no prior criminal record, Lusczynski said, and state records show no record for Mills.

Gadson's wife filed for divorce Dec. 1 in Westhope, N.D., and a judgment was entered Dec. 28. Just Friday, his response to a child support questionnaire was filed with the court.

The Thonotosassa home where the shooting occurred is owned by his mother, a registered nurse, according to licensing and property records.

Sheriff's investigators have not yet said what led to the gunfire.

At a 4 p.m. news conference, Lusczynski said the agency was awaiting a search warrant to enter the home. A short while later, a forensics vehicle arrived.

Relatives gathered along the road outside the home turned away reporters' questions.

Times senior news researcher John Martin contributed to this report. Contact Anastasia Dawson at adawson@tampabay.com or (813) 226-3377.