A Labrador retriever named Penny hit the jackpot when she and her handler were conducting a probation compliance check Wednesday at a Glendora home.

The individual on probation at the home wasn't allowed to have firearms, but Penny's nose led her to ammunition and guns inside the house and garage. The probationer and his brother, the suspected owner of the rifle, were arrested by Glendora police.

Penny found boxes full of ammunition in the living room and a dresser drawer, then discovered a bag with two handguns in a bedroom and a black gun case containing another handgun under the bed. She alerted her handler to several loaded high-capacity magazines in the garage, where the team also found an illegal AK-47 locked in a cabinet.

Penny and her handler are part of the Los Angeles County Probation Department Canine Detection Team. The department's canine detection program, approved for funding in November 2016, includes specially trained dogs who can detect narcotics and firearms.

The team also has two springer spaniels, Chloe and Lola. The dogs and their handlers go through about 80 hours of training before hitting the streets on probation compliance searches.