ESCONDIDO, Calif. - Investigators looking for an out-of-compliance registered sex offender in Escondido Wednesday spotted a man who appeared to be carrying an assault rifle into a home in the area, prompting a several-hour SWAT standoff that ended with three arrests.

Members of the San Diego Sexual Assault Felony Enforcement Task Force notified Escondido police shortly before 9:30 a.m. that they believed the wanted man, Miguel Angel Juarez, 37, was in a house in the 500 block of South Spruce Street, near Westside Park, Lt. Chris Wynn said.

A few minutes later, a man was spotted walking into the residence, carrying what appeared to be a high-powered rifle, according to Wynn.

Patrol officers surrounded the home and called out to anyone inside to exit and surrender. A short time later, two people came out onto a porch, and one was detained immediately. The other made a failed attempt to escape on foot. That suspect, 19-year-old David Mata Betancort, was captured nearby, Wynn said.

Police determined that two other men -- one of them Juarez -- remained in the home, but neither was responding to officers' attempts to make contact. Due to the possible presence of a gun in the residence, a Special Weapons and Tactics team was sent to the scene.

About 1:30 p.m., one suspect came outside and was taken into custody without incident. When the other man continued refusing to surrender, the SWAT personnel set off flash-concussion devices next to the residence, after which he finally exited and surrendered.

The third suspect was identified as Christopher David Sarenana, 24, of Escondido. He was arrested on a probation violation.

Betancort was booked on suspicion of violating a gang injunction. Police determined that he had been the one carrying the rifle, which turned out to be an airsoft-style pellet gun.

Juarez was expected to be charged in connection with two misdemeanor warrants and for failing to register as a sex offender.

"There is gang activity here, but this is scary," said neighbor Robert Perry.

The first of the suspects to be detained was released after being questioned.

The three arrested men were booked into county jail in Vista.

In the late afternoon, officers served a search warrant at the home where the standoff had taken place. They found a disassembled handgun, several pellet guns and a small amount of methamphetamine, police said.