This brahmana, Gopala Capala, wanted to defame Srivasa Thakura by proving that he was actually a sakta, or a worshiper of Bhavani, the goddess Durga, but was externally posing as a Vaisnava

Expressions researched:
"This brāhmaṇa, Gopāla Cāpāla, wanted to defame Śrīvāsa Ṭhākura by proving that he was actually a śākta, or a worshiper of Bhavānī, the goddess Durgā, but was externally posing as a Vaiṣṇava"

CC Adi-lila

Gopāla Cāpāla, wanted to defame Śrīvāsa Ṭhākura by proving that he was actually a śākta, or a worshiper of Bhavānī, the goddess Durgā, but was externally posing as a Vaiṣṇava.

CC Adi 17.37-38, Translation and Purport:

One night while kīrtana was going on inside Śrīvāsa Ṭhākura's house, a brāhmaṇa named Gopāla Cāpāla, the chief of the nonbelievers, who was talkative and very rough in his speech, placed all the paraphernalia for worshiping the goddess Durgā outside Śrīvāsa Ṭhākura's door.

This brāhmaṇa, Gopāla Cāpāla, wanted to defame Śrīvāsa Ṭhākura by proving that he was actually a śākta, or a worshiper of Bhavānī, the goddess Durgā, but was externally posing as a Vaiṣṇava. In Bengal there is perpetual competition between the devotees of goddess Kālī and the devotees of Lord Kṛṣṇa. Generally Bengalis, especially those who are meat-eaters and drunkards, are very much attached to worshiping the goddesses Durgā, Kālī, Śītalā and Caṇḍī. Such devotees, who are known as śāktas, or worshipers of the śakti-tattva, are always envious of Vaiṣṇavas. Since Śrīvāsa Ṭhākura was a well-known and respected Vaiṣṇava in Navadvīpa, Gopāla Cāpāla wanted to reduce his prestige by bringing him down to the platform of the śāktas. Therefore outside Śrīvāsa Ṭhākura's door he placed various paraphernalia for worshiping Bhavānī, the wife of Lord Śiva, such as a red flower, a plantain leaf, a pot of wine, and reddish sandalwood paste. In the morning, when Śrīvāsa Ṭhākura saw all this paraphernalia in front of his door, he called for the respectable gentlemen of the neighborhood and showed them that at night he was worshiping Bhavānī. Very sorry, these gentlemen called for a sweeper to cleanse the place and purify it by sprinkling water and cow dung there. This incident concerning Gopāla Cāpāla is not mentioned in the Caitanya-bhāgavata.